'How soon before it walks again?' asked Cronus.

'Not soon enough,' snarled Maven. 'Can you believe they were going to scrap Equitos Bellum?'

Cronus shook his head. 'A mount with so fine a pedigree? Madness. Thank the Machine for the Old Man, eh?'

When Maven had begun to suspect that the master of the forge was going to condemn Equitos Bellum, he had petitioned Lords Caturix and Verticorda to intervene to save his mount. By the time the battle assayers had finished their inspection, there had been no word, and the giant breaker-servitors were standing by.

Maven had placed himself between them and Equitos Bellum with his sidearm drawn. He remembered the lethal purpose filling him as he prepared to defend his wounded mount.

With the breakers moving in and Maven ready to kill, word had come down to the repair hangars from the Lightning Hall.

Equitos Bellum was to walk again.

Maven had stood vigil over his stricken machine ever since, as though fearing the order to restore Equitos Bellum to a war footing could be rescinded at any moment.

Cronus put a reassuring hand on Maven's shoulder.

'Your mount will be battle ready before you know it.'

'I know, but I wonder if it'll ever be as it was before.'

'How so?'

'Ever since the battle at Maximal's reactor I've felt… I'm not sure, a sense of things unfinished, as if neither of us will be whole again until we avenge ourselves.'

'Avenge yourselves on what?' asked Cronus. 'Whatever attacked the reactor was destroyed in the explosion. It's a damned miracle you survived.'

Maven pointed to the damaged Knight. 'I know it's a miracle - as surely as I know that whatever did this is still out there. Equitos Bellum can feel it out there and so can I.'

Cronus shook his head. 'That's just lingering somatic pain-memory. It's gone, Raf.'

'I don't believe that and nothing you say to me will convince me otherwise,' said Maven. 'It was void protected, Leo. It could easily have survived the explosion and escaped into the pallidus wastelands or the deep canyons of the Ulysses Fossae.'

'I read the after-action report,' said Cronus. 'But void-shielded? Only Titans have voids. Maybe it just had reserve power fields.'

'Yeah, or maybe I just missed,' snapped Maven. 'Or maybe heat bloom from the reactor made it look like it was shielded. Damn it, Leo, I know what I saw. It was shielded and it's still out there, I know it.'

'What makes you so sure it's still out there?'

Maven hesitated before answering. He looked up into Leopold's stolid face and knew that of all the people he could talk to about his lingering suspicions without fear of ridicule, it was Cronus. 'I couldn't feel anything from the machine,' he said. 'It was cold, like a dead thing.'

'A dead thing? What do you mean?'

'It was as if… as if there was nothing inside it,' whispered Maven. 'I didn't get any sense of a pilot: no battle fury, no flair and certainly no triumph when it hit me.'

'So you think it was a robot?'

Maven shook his head. 'No, it wasn't a robot. It reacted in ways that battle wetware can't, at least none I'm aware of .'

Both men knew that mono-tasked fighting robots were no match for skilled pilots, who could easily outfight machines with limited parameters of action.

'So what do you think it was?' asked Cronus.

Maven shrugged. 'It wasn't a robot,' he sighed. 'But then its fire patterns were so… textbook, like a rookie pilot on his first mission. I think that's the only reason I was able to get away without it taking me down. It was as if it had all the skills to destroy me, it just didn't know how to use them properly.'

'Then what are you going to do about it?'

'I'm going to hunt it down and kill it,' said Maven.

In the darkest vaulted chambers beneath Olympus Mons, three figures made their way down a cloistered passageway and through dust that had not been disturbed for two centuries. Tunnels and passages branched off into darkness, hewn into the bedrock of Mars thousands of years ago, but the three figures followed an unerring path through the maze as though pulled by an invisible cord or guided by an inaudible signal.

As he made his way through the shadowed tunnels, Kelbor-Hal surprised himself by detecting elevated adrenal levels and increased production of interleukins that in an unaugmented human would indicate excitement.

The automaton followed behind him, oblivious to the momentous role its master was about to play in the future history of Mars. The Fabricator General turned his hooded head to face Regulus, the adept moving with a loping mechanical grace as they delved into the depths of the planet and towards their destiny:

The Vaults of Moravec.

Secrets that could not even be imagined awaited within that forgotten repository - a wealth of knowledge that had lain untapped and unexamined for a millennium. Such a waste of resource. Such a crime to disavow the legacy of the past.

A gaggle of floating servo-skulls accompanied them, swaying lumen globes held in pincer callipers hanging from their jaws.

Dust billowed in their wake and the metallic ring of their footsteps echoed from the dry, flaking walls as they travelled ever onwards. Regulus turned another corner, taking them through an echoing chamber with numerous tunnels branching off into the unknown.

Without pause, Regulus chose the seventh tunnel along the western wall and led them onwards, past dusty tombs, empty cells and bone-stacked alcoves of unknown worthies who had died and been placed in empty reliquaries in ages past.

They passed open chambers piled high with dust-covered books, forgotten volumes of lore and chained bookcases of ledgers, records and the personal logs of long-dead adepts. Kelbor-Hal saw open caverns with giant machines, seized solid with rust or so corroded as to be unrecognisable.

This was the legacy of leaving technology untapped, the only possible outcome of the Emperor's decree that the Vault of Moravec remain unopened. With each sight, he grew more and more convinced that this path was the right one, that this gift of Horus Lupercal was one that should be accepted.

Kelbor-Hal's positioning matrix informed him that he was precisely nine hundred and thirty-five metres beneath the surface of Mars. He traced their route on a glowing map projected before him and recorded every step of the journey on a memory coil buried deep in his lumbar region.

It galled the Fabricator General that he needed Regulus to guide him through the maze, for he had travelled this way once before and should have been able to retrieve the route from his internal records.

It had been two hundred years ago when Kelbor-Hal had last seen the vault of Moravec. Together with his golden-armoured Custodians, the Emperor had led the way into the dusty sepulchres beneath Olympus Mons. The Emperor followed the path through the maze of tunnels towards the lost vault, though how the ruler of Terra had known its location had never been satisfactorily explained.

Nor had the need that had driven him to find the vaults been expressed.

Kelbor-Hal had put aside such concerns, eagerly anticipating studying the unknown technologies that lay within the hidden catacombs beneath Olympus Mons.

When the vault was located, however, the Emperor simply stood before it without opening it. He had placed his hand on the sealed entrance to the vault with his eyes closed, and stood as immobile as a statue for sixteen point one five minutes before turning and leading his warriors back to the surface, despite Kelbor-Hal's protests.

It had been forbidden to store any record of the path to Moravec's vault, though Kelbor-Hal had, of course, secretly activated his cartographic memory buffers. However, upon returning to the surface, he had found them to be empty of any record of the journey. As though it had never happened.